/Engine/Source/Runtime/Core/Public/Algo/SelectRandomWeighted.h
Randomly select an element from a range of elements, weighted by a projection. The chance of any element being chosen is its weight / the sum of all the weights in the range. Negative- or zero- weighted elements will not be chosen or count toward the total.
namespace Algo { template<typename RangeType, typename ProjectionType> auto Algo::SelectRandomWeightedBy ( RangeType && Range, ProjectionType Proj ) }